Aromatic underlayer

ABSTRACT

Compounds having three or more alkynyl moieties substituted with an aromatic moiety having one or more of certain substituents are useful in forming underlayers useful in semiconductor manufacturing processes.

The present invention relates generally to the field of manufacturingelectronic devices, and more specifically to the field of materials foruse as underlayers in semiconductor manufacture.

It is well-known in lithographic processes that a resist pattern cancollapse due to surface tension from the developer used if the resistpattern is too tall (high aspect ratio). Multilayer resist processes(such as three- and four-layer processes) have been devised which canaddress this issue of pattern collapse where a high aspect ratio isdesired. Such multilayer processes use a resist top layer, one or moremiddle layers, and a bottom layer (or underlayer). In such multilayerresist processes, the top photoresist layer is imaged and developed intypical fashion to provide a resist pattern. The pattern is thentransferred to the one or more middle layers, typically by etching. Eachmiddle layer is selected such that a different etch process is used,such as different plasma etches. Finally, the pattern is transferred tothe underlayer, typically by etching. Such middle layers may be composedof various materials while the underlayer materials are typicallycomposed of high carbon content materials. The underlayer material isselected to provide desired antireflective properties, planarizingproperties, as well as etch selectivity.

The incumbent technologies for underlayer include chemical vapordeposited (CVD) carbon and solution processed high-carbon contentpolymers. The CVD materials have several significant limitationsincluding high cost of ownership, inability to form a planarizing layerover topography on a substrate, and high absorbance at 633 nm which isused for pattern alignment. For these reasons, the industry has beenmoving to solution processed high-carbon content materials asunderlayers. The ideal underlayer needs to meet the followingproperties: capable of being cast onto a substrate by a spin-coatingprocess, thermal-set upon heating with low out-gassing and sublimation,soluble in common processing solvents for good equipment compatibility,have appropriate n and k values to work in conjunction with currentlyused silicon hardmask and bottom antireflectant (BARC) layers to impartlow reflectivity necessary for photoresist imaging, and be thermallystable up to >400° C. so as to not be damaged during subsequentsilicon-oxy-nitride (SiON) CVD processes.

It is well-known that materials of relatively low molecular weight haverelatively low viscosity, and flow into features in a substrate, such asvias and trenches, to afford planarizing layers. Underlayer materialsmust be able to planarize with relatively low out-gassing up to 400° C.For use as a high-carbon content underlayer, it is imperative for anycomposition to be thermally set upon heating. U.S. Pat. No. 9,581,905 B2discloses compounds of the formula

where R₁, R₂ and R₃ each independently represent the formulaR^(A)—C≡C—R^(B)—, where R^(A) can be, inter alia, an aryl groupsubstituted with at least one of a hydroxyl group and an aryl group, andR^(B) is a single bond or an aryl group, where such compounds are usefulin forming underlayers in the manufacture of semiconductor devices. Suchcompounds cure at relatively high temperatures. There remains a need formaterials that cure at relatively lower temperatures and that are usefulfor forming underlayers in semiconductor manufacturing processes.

The present invention provides a method comprising: (a) providing anelectronic device substrate; (b) coating a layer of a coatingcomposition comprising one or more curable compounds on a surface of theelectronic device substrate, wherein the one or more curable compoundscomprise an aromatic core chosen from a C₅₋₆ aromatic ring and a C₉₋₃₀fused aromatic ring system and three or more substituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is a substituent chosen fromOR¹, protected hydroxyl, carboxyl, protected carboxyl, SR¹, protectedthiol, —O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H,C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² ischosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core; (c) curing the layer of thecurable compound to form an underlayer; (d) coating a layer of aphotoresist on the underlayer; (e) exposing the photoresist layer toactinic radiation through a mask; (f) developing the exposed photoresistlayer to form a resist pattern; and (g) transferring the pattern to theunderlayer to expose portions of the electronic device substrate.

Also provided by the present invention is an electronic devicecomprising an electronic device substrate having a layer of a polymercomprising as polymerized units one or more curable compounds on asurface of the electronic device substrate, wherein the one or morecurable compounds comprise an aromatic core chosen from a C₅₋₆ aromaticring and a C₉₋₃₀ fused aromatic ring system and three or moresubstituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is a substituent chosen fromOR¹, protected hydroxyl, carboxyl, protected carboxyl, SR¹, protectedthiol, —O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H,C₁₋₁₀ alkyl, C₂₋₁₀unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² ischosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core.

The present invention further provides a compound of formula (2)

wherein Ar^(c) is an aromatic core having from 5 to 30 carbon atoms;Ar¹, Ar², and Ar³ are each independently an aromatic ring or fusedaromatic ring system having from 5 to 30 carbons; Y is a single covalentchemical bond, a divalent linking group, or a trivalent linking group;Z¹ and Z² are independently a substituent chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosenfrom H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to4; y1+each y2≥3; w=0 to 2; and z equals 0 to 2; wherein z=1 when Y is asingle covalent chemical bond or a divalent linking group; and z=2 whenY is a trivalent linking group; provided that Ar^(c) and each Ar¹ arenot phenyl when w=0.

Still further, the present invention provides a method comprising: (a)providing an electronic device substrate; (b) coating a layer of acoating composition comprising one or more curable compounds of formula(2)

wherein Ar^(c) is an aromatic core having from 5 to 30 carbon atoms;Ar¹, Ar², and Ar³ are each independently an aromatic ring or fusedaromatic ring system having from 5 to 30 carbons; Y is a single covalentchemical bond, a divalent linking group, or a trivalent linking group;Z¹ and Z² are independently a substituent chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosenfrom H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to4; y1+each y2≥3; w=0 to 2; and z equals 0 to 2; wherein z=1 when Y is asingle covalent chemical bond or a divalent linking group; and z=2 whenY is a trivalent linking group on a surface of the electronic devicesubstrate; (c) curing the layer of the curable compound to form anunderlayer; (d) coating a layer of a photoresist on the underlayer; (e)exposing the photoresist layer to actinic radiation through a mask; (f)developing the exposed photoresist layer to form a resist pattern; and(g) transferring the pattern to the underlayer to expose portions of theelectronic device substrate.

Also provided by the present invention is a process for filling a gap(or aperture), comprising: (a) providing a semiconductor substratehaving a relief image on a surface of the substrate, the relief imagecomprising a plurality of gaps to be filled; (b) applying a coatinglayer of one or more compounds of formula (2) over the relief image; and(c) heating the coating layer at a temperature sufficient to cure thecoating layer.

It will be understood that when an element is referred to as being “on”another element, it can be directly adjacent to the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present. As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items.

It will also be understood that although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the present invention.

As used throughout this specification, the following abbreviations shallhave the following meanings, unless the context clearly indicatesotherwise: ° C.=degree Celsius; g=gram; mg=milligram; L=liter;mL=milliliter; A=angstrom; nm=nanometer; μm=micron=micrometer;mm=millimeter; sec.=second; min.=minute; hr.=hour; DI=deionized; andDa=dalton. “Wt %” refers to percent by weight based on the total weightof a referenced composition, unless otherwise specified. Unlessotherwise specified, all amounts are wt % and all ratios are molarratios. All numerical ranges are inclusive and combinable in any order,except where it is clear that such numerical ranges are constrained toadd up to 100%. The articles “a”, “an” and “the” refer to the singularand the plural. “Alkyl” refers to linear, branched and cyclic alkylunless otherwise specified. As used herein, “alkyl” refers to an alkaneradical, and includes alkane monoradicals, diradicals (alkylene), andhigher-radicals. “Halo” refers to fluoro, chloro, bromo, and iodo.Unless otherwise noted, “alkyl” includes “heteroalkyl”. The term“heteroalkyl” refers to an alkyl group with one or more heteroatoms,such as nitrogen, oxygen, sulfur, phosphorus, replacing one or morecarbon atoms within the radical, for example, as in an ether or athioether. In one preferred embodiment, “alkyl” does not include“heteroalkyl”. If no number of carbons is indicated for any alkyl orheteroalkyl, then 1-12 carbons are contemplated.

“Aryl” includes aromatic carbocycles and aromatic heterocycles. The term“aryl” refers to an aromatic radical, and includes monoradicals,diradicals (arylene), and higher-radicals. It is preferred that arylmoieties are aromatic carbocycles. “Substituted aryl” refers to any arylmoiety having one or more of its hydrogens replaced with one or moresubstituents chosen from halogen, C₁₋₆-alkyl, halo-C₁₋₆-alkyl,C₁₋₆-alkoxy, halo-C₁₋₆-alkoxy, phenyl, and phenoxy, preferably fromhalogen, C₁₋₆-alkyl, halo-C₁₋₄-alkyl, C₁₋₆-alkoxy, halo-C₁₋₄-alkoxy, andphenyl, and more preferably from halogen, C₁₋₆-alkyl, C₁₋₆-alkoxy,phenyl, and phenoxy. Preferably, a substituted aryl has from 1 to 3substituents, and more preferably 1 or 2 substituents. As used herein,the term “polymer” includes oligomers. The term “oligomer” refers todimers, trimers, tetramers and other polymeric materials that arecapable of further curing. By the term “curing” is meant any process,such as polymerization or condensation, that increases the overallmolecular weight of the present resins, removes solubility enhancinggroups from the present oligomers, or both increases the overallmolecular weight and removes solubility enhancing groups. “Curable”refers to any material capable of being cured under certain conditions.As used herein, “gap” refers to any aperture on a semiconductorsubstrate that is intended to be filled with a gap-filling composition.

Aromatic underlayers are formed in the manufacture of electronic devicesaccording to a method comprising: (a) providing an electronic devicesubstrate; (b) coating a layer of a coating composition comprising oneor more curable compounds on a surface of the electronic devicesubstrate, wherein the one or more curable compounds comprise anaromatic core chosen from a C₅₋₆ aromatic ring and a C₉₋₃₀ fusedaromatic ring system and three or more substituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosenfrom H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core; (c) curing the layer of thecurable compound to form an underlayer; (d) coating a layer of aphotoresist on the underlayer; (e) exposing the photoresist layer toactinic radiation through a mask; (f) developing the exposed photoresistlayer to form a resist pattern; and (g) transferring the pattern to theunderlayer to expose portions of the electronic device substrate. Next,the substrate is patterned, and the patterned underlayer is removed. Inone preferred embodiment, a layer of photoresist is coated directly onthe underlayer. In an alternate preferred embodiment, a layer of one ormore of a silicon-containing composition, an organic antireflectivecomposition (BARC), and a combination thereof is coated directly on theunderlayer before step (d) to form a middle layer and a layer ofphotoresist is coated directly on the middle layer. When asilicon-containing middle layer is used, the pattern is transferred tothe silicon-containing middle layer after step (f) and before step (g).

A wide variety of electronic device substrates may be used in thepresent invention, such as: packaging substrates such as multichipmodules; flat panel display substrates; integrated circuit substrates;substrates for light emitting diodes (LEDs) including organic lightemitting diodes (OLEDs); semiconductor wafers; polycrystalline siliconsubstrates; and the like, with semiconductor wafers being preferred.Such substrates are typically composed of one or more of silicon, polysilicon, silicon oxide, silicon nitride, silicon oxynitride, silicongermanium, gallium arsenide, aluminum, sapphire, tungsten, titanium,titanium-tungsten, nickel, copper, and gold. Suitable substrates may bein the form of wafers such as those used in the manufacture ofintegrated circuits, optical sensors, flat panel displays, integratedoptical circuits, and LEDs. As used herein, the term “semiconductorwafer” is intended to encompass “a semiconductor substrate,” “asemiconductor device,” and various packages for various levels ofinterconnection, including a single-chip wafer, multiple-chip wafer,packages for various levels, or other assemblies requiring solderconnections. Such substrates may be any suitable size. Preferred wafersubstrate diameters are 200 mm to 300 mm, although wafers having smallerand larger diameters may be suitably employed according to the presentinvention. As used herein, the term “semiconductor substrate” includesany substrate having one or more semiconductor layers or structureswhich may optionally include active or operable portions ofsemiconductor devices. A semiconductor device refers to a semiconductorsubstrate upon which at least one microelectronic device has been or isbeing batch fabricated.

Optionally, a layer of an adhesion promoter may be applied to thesubstrate surface before the deposition of the present coatingcompositions, which is subsequently cured to form the underlayer. If anadhesion promoter is desired, any suitable adhesion promoter for polymerfilms may be used, such as silanes, preferably organosilanes such astrimethoxyvinylsilane, triethoxyvinylsilane, hexamethyldisilazane, or anaminosilane coupler such as gamma-aminopropyltriethoxysilane.Particularly suitable adhesion promoters include those sold under the AP3000, AP 8000, and AP 9000S designations, available from Dow ElectronicMaterials (Marlborough, Mass.).

Coating compositions useful in the present invention comprise one ormore curable compounds comprising an aromatic core chosen from a C₅₋₆aromatic ring and a C₉₋₃₀ fused aromatic ring system and three or moresubstituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H,C₁₋₁₀-alkyl, C₂₋₁₀-unsaturated hydrocarbyl, and C₅₋₃₀-aryl; each R² ischosen from H, C₁₋₁₀-alkyl, C₂₋₁₀-unsaturated hydrocarbyl, C₅₋₃₀-aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core. It is preferred that each Z isindependently chosen from OR¹, protected hydroxyl, carboxyl (C(═O)OH),protected carboxyl, SH, fluorine, and NHR². More preferably, each Z isindependently chosen from hydroxyl (OH), protected hydroxyl, OCH₂C≡CH,C(═O)OH, protected carboxyl, and NHR², yet more preferably from OH,protected hydroxyl, OCH₂C≡CH, carboxyl, and protected carboxyl, andstill more preferably from OH and protected hydroxyl. Each R¹ isindependently chosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl,and C₅₋₃₀ aryl, and more preferably from H, C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl,C₂₋₁₀-alkynyl, and C₅₋₃₀ aryl. In one preferred embodiment, R¹ is H.Preferably, R² is chosen from H, C₁₋₁₀-alkyl, C₂₋₁₀-unsaturatedhydrocarbyl, and C₅₋₃₀-aryl, and more preferably from H, C₁₋₁₀-alkyl,C₂₋₁₀-alkenyl and C₂₋₁₀-alkynyl. As used herein, the term “aromaticcore” refers to a single aromatic ring or a fused aromatic ring systemto which at least two moieties of formula (1) are attached. The aromaticcore may optionally be substituted with one or more substituents chosenfrom C₁₋₂₀-aliphatic or cycloaliphatic moiety and C₅₋₃₀-aryl moiety.Preferably, the aromatic core is chosen from pyridine, benzene,naphthalene, quinoline, isoquinoline, carbazole, anthracene,phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene,benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, morepreferably from benzene, naphthalene, carbazole, anthracene,phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene,benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, and stillmore preferably from benzene, naphthalene, anthracene, phenanthrene,pyrene, coronene, triphenylene, chrysene, and phenalene. In formula (1),it is preferred that each Ar¹ is independently chosen from pyridine,benzene, naphthalene, quinoline, isoquinoline, anthracene, phenanthrene,pyrene, coronene, triphenylene, chrysene, phenalene, benz[a]anthracene,dibenz[a,h]anthracene, and benzo[a]pyrene, more preferably from benzene,naphthalene, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene, and even more preferably from benzene, naphthalene,anthracene, phenanthrene, pyrene, coronene, triphenylene, chrysene, andphenalene. It is preferred that x=1 or 2, and more preferably x=1. Thepresent curable compounds have at least three moieties of formula (1)wherein at least two substituents of formula (1) are attached directlyto the aromatic core. The present curable compounds may have anysuitable number of the moieties of formula (1) such as from 3 to 10,preferably 3 to 8, more preferably from 3 to 6, and even more preferably3 or 4. It is further preferred that the present curable compounds havefrom 2 to 4 moieties of formula (1) attached directly to the aromaticcore.

In one embodiment, preferred curable compounds useful in the presentcoating compositions are those of formula (2)

wherein Ar^(c) is an aromatic core having from 5 to 30 carbon atoms;Ar¹, Ar², and Ar³ are each independently an aromatic ring or fusedaromatic ring system having from 5 to 30 carbons; Y is a single covalentchemical bond, a divalent linking group, or a trivalent linking group;Z¹ and Z² are independently chosen from OR¹, protected hydroxyl,carboxyl, protected carboxyl, SR¹, protected thiol, —O—C(═O)—C₁₋₆-alkyl,halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀ alkyl, C₂₋₁₀unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl, C(═O)—R¹, andS(═O)₂—R¹; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to 4; y1+eachy2≥3; w=0 to 2; and z equals 0 to 2; wherein z=1 when Y is a singlecovalent chemical bond or a divalent linking group; and z=2 when Y is atrivalent linking group. It is preferred that Ar^(c) is an aromatic corehaving from 5 to 25 carbon atoms, and more preferably from 5 to 20carbon atoms. Suitable aromatic cores for Ar^(c) include, withoutlimitation, pyridine, benzene, naphthalene, quinoline, isoquinoline,carbazole, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene, preferably benzene, naphthalene, carbazole, anthracene,phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene,benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, and morepreferably benzene, naphthalene, anthracene, phenanthrene, pyrene,coronene, triphenylene, chrysene, and phenalene. It is preferred thatAr¹ is chosen from benzene, pyridine, naphthalene, quinoline,isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene. More preferably, each of Ar¹, Ar², and Ar³ isindependently chosen from pyridine, benzene, naphthalene, quinoline,isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene, more preferably from benzene, naphthalene, anthracene,phenanthrene, pyrene, coronene, triphenylene, chrysene, phenalene,benz[a]anthracene, dibenz[a,h]anthracene, and benzo[a]pyrene, and yetmore preferably from benzene, naphthalene, anthracene, phenanthrene,pyrene, coronene, triphenylene, chrysene, and phenalene. It is furtherpreferred that Ar^(c) is chosen from pyridine, benzene, naphthalene,quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene,triphenylene, chrysene, phenalene, benz[a]anthracene,dibenz[a,h]anthracene, and benzo[a]pyrene, and each of Ar¹, Ar², andAr^(a) is independently chosen from pyridine, benzene, naphthalene,quinoline, isoquinoline, anthracene, phenanthrene, pyrene, coronene,triphenylene, chrysene, phenalene, benz[a]anthracene,dibenz[a,h]anthracene, and benzo[a]pyrene. It is preferred that each Z¹and Z² are independently chosen from chosen from OR¹, protectedhydroxyl, carboxyl (C(═O)OH), protected carboxyl, SH, fluorine, NHR²,more preferably from hydroxyl (OH), protected hydroxyl, OCH₂C≡CH,C(═O)OH, protected carboxyl, and NHR², yet more preferably from OH,protected hydroxyl, OCH₂C≡CH, carboxyl, and protected carboxyl, andstill more preferably from OH and protected hydroxyl. Each R¹ isindependently chosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl,and C₅₋₃₀ aryl, and more preferably from H, C₁₋₁₀-alkyl, C₂₋₁₀-alkenyl,C₂₋₁₀-alkynyl, and C₅₋₃₀ aryl. In one preferred embodiment, R¹ is H.Preferably, R² is chosen from H, C₁₋₁₀-alkyl, C₂₋₁₀-unsaturatedhydrocarbyl, and C₅₋₃₀-aryl, and more preferably from H, C₁₋₁₀-alkyl,C₂₋₁₀-alkenyl and C₂₋₁₀-alkynyl. It is preferred that each Z¹ is thesame. It is also preferred that each Z² is the same. It is furtherpreferred that Z¹═Z². It is preferred that each of x1 and x2 areindependently chosen from 1 to 3, more preferably are independently 1 or2, and yet more preferably are each 1. Preferably, each y2=0 to 2. It ispreferred that y1+each y2=3 to 8, more preferably 3 to 6, and yet morepreferably 3 or 4. Preferably, w=0 to 1. In one preferred embodiment,Ar^(c) and each Ar¹ are not phenyl when w=0. In one preferredembodiment, Y is a single covalent bond. In another preferredembodiment, Y is a divalent or trivalent linking group. Exemplarylinking groups for Y include, but are not limited to, 0, S, N(R³)_(r),S(═O)₂, CR⁴R⁵, a bis-imide moiety, a bis-etherimide moiety, abis-ketoimide moiety, a bis-benzoxazole moiety, a bis-benzimidazolemoiety, and a bis-benzothiazole moiety, wherein r=0 or 1, and preferablylinking groups for Y are O, N(R³)_(w), and CR⁴R⁵. R³ is**—C(═O)—C₅₋₃₀-aryl or **—S(═O)₂—C₅₋₃₀-aryl, wherein ** is the point ofattachment to N. R⁴ and R⁵ are independently chosen from H, C₁₋₁₀-alkyland C₅₋₁₀-aryl, and R⁴ and R⁴ may be taken together along with thecarbon to which they are attached to form a 5- or 6-membered ring whichmay be fused to one or more aromatic rings. One suitable linking groupwhen Y═CR⁴R⁵ is a fluorenyl moiety of the following formula (A)

wherein * denotes the point of attachment to Ar^(c) and Ar². A suitablebis-imide moiety linking group for Y is shown by formula (B) and formula(C) where Y¹ is a single covalent bond or a C₅₋₃₀-arylene, wherein *denotes the point of attachment to Ar^(c) and Ar². Suitablebis-etherimide and bis-ketoimide moieties are those of formula (C)wherein Y¹═O or —C(═O)—, respectively, and wherein * denotes the pointof attachment to Ar^(c) and Ar². Suitable bis-benzoxazole,bis-benzimidazole, and bis-benzothiazole moieties are those of formula(D), wherein G=O, NH, and S, respectively, and wherein Y² is a singlecovalent bond or a C₅₋₃₀-arylene, and wherein * denotes the point ofattachment to Ar^(c) and Ar².

Protected carboxyl groups for Z, Z¹ and Z² of formulas (1) and (2) areany group which is cleavable under certain conditions to yield acarboxyl group. Such protected carboxyl groups may be cleaved by heat,acid, base or a combination thereof, preferably by heat, acid or acombination thereof, and more preferably by heat. Exemplary protectedcarboxyl groups include esters, such as benzyl esters and esters havinga quaternary carbon bonded directly to the alkoxy oxygen of the estergroup. It is preferred that the protected carboxyl group is an esterhaving a quaternary carbon bonded directly to the alkoxy oxygen of theester group, and more preferably the ester has the formulaY—C(O)—O—CR′R″R′″, where Y is an organic residue, and each of R′, R″ andR′″ are independently chosen from C₁₋₁₀alkyl. Preferred protectedcarboxyl groups include: tert-butyl esters; 1-alkyklcyclopentyl esterssuch as 1-methylcyclopentyl esters and 1-ethylcyclopentyl esters;2,3-dimethyl-2-butyl esters; 3-methyl-3-pentyl esters;2,3,3-trimethyl-3-butyl esters; 1,2-dimethylcyclopentyl esters;2,3,4-trimethyl-3-pentyl esters; 2,2,3,4,4-pentamethyl-3-pentyl esters;and adamantyl esters such as hydroxyadamantyl esters andC₁₋₁₂alkyladamantyl esters. Each of the aforementioned protectedcarboxyl groups can be cleaved by one or more of heat, acid or base.Preferably, the protected carboxyl groups are cleaved using heat, acidor a combination of heat and acid, and more preferably by heat. Forexample, these protected carboxyl groups can be cleaved at a pH of ≤4and preferably ≤1. Such protected carboxyl groups may be cleaved at roomtemperature when in exposed to a pH in the range of 1 to 4. When the pHis <1, such protected carboxyl groups are typically heated toapproximately 90 to 110° C., and preferably to approximately 100° C.Alternatively, when the protected carboxyl group is an ester having aquaternary carbon bonded directly to the alkoxy oxygen of the estergroup, it can be cleaved by heating to a suitable temperature, such as≥125° C., preferably from 125 to 250° C., and more preferably from 150to 250° C. Such protected carboxyl groups, and their conditions of use,are well-known in the art, such as U.S. Pat. No. 6,136,501, whichdiscloses various ester groups having a quaternary carbon bondeddirectly to the alkoxy oxygen of the ester group.

Protected hydroxyl groups suitable for Z, Z¹ and Z² of formulas (1) and(2) are any group which is cleavable under certain conditions to yield ahydroxyl group. Such protected hydroxyl groups may be cleaved by heat,acid, base or a combination thereof. Exemplary protected hydroxyl groupsinclude: ethers such as methoxymethyl ethers, tetrahydropyranyl ethers,tert-butyl ethers, allyl ethers, benzyl ethers, tert-butyldimethylsilylethers, tert-butyldiphenylsilyl ethers, acetonides, and benzylideneacetals; esters such as pivalic acid esters and benzoic acid esters; andcarbonates such as tert-butylcarbonate. Each of the aforementionedprotected hydroxyl groups can be cleaved under acidic or alkalineconditions, and preferably under acidic conditions. More preferably, theprotected hydroxyl groups are cleaved using acid or a combination ofacid and heat. For example, these protected hydroxyl groups can becleaved at a pH of ≤4 and preferably ≤1. Such protected hydroxyl groupsmay be cleaved at room temperature when exposed to a pH in the range of1 to 4. When the pH is <1, such protected hydroxyl groups are typicallyheated to approximately 90 to 110° C., and preferably to approximately100° C. Such protected hydroxyl groups, and their conditions of use, arewell-known in the art.

Protected thiol groups suitable for Z, Z¹ and Z² of formulas (1) and (2)are any group which is cleavable under certain conditions to yield athiol group. Such protected thiol groups may be cleaved by heat, acid,base or a combination thereof. Exemplary protected thiol groups include:ethers such as methoxymethyl thioethers, tetrahydropyranyl thioethers,tert-butyl thioethers, allyl thioethers, benzyl thioethers,tert-butyldimethylsilyl thioethers, tert-butyldiphenylsilyl thioethers,thioacetonides, and benzylidene thioacetals; thioesters such as pivalicacid thioesters and benzoic acid thioesters; and thiocarbonates such astert-butylthiocarbonate. Each of the aforementioned protected thiolgroups can be cleaved under acidic or alkaline conditions, andpreferably under acidic conditions. More preferably, the protected thiolgroups are cleaved using acid or a combination of acid and heat. Forexample, these protected thiol groups can be cleaved at a pH of ≤4 andpreferably ≤1. Such thiol groups may be cleaved at room temperature whenexposed to a pH in the range of 1 to 4. When the pH is <1, suchprotected thiol groups are typically heated to approximately 90 to 110°C., and preferably to approximately 100° C. Such protected thiol groups,and their conditions of use, are well-known in the art.

In addition to the one or more curable compounds described above, thepresent coating compositions may optionally comprise, and preferably docomprise, one or more organic solvents. Suitable organic solvents areany that dissolve the one or more curable compounds, and preferably areorganic solvents conventionally used in the manufacture of electronicdevices. Organic solvents may be used alone or a mixture of organicsolvents may be used. Suitable organic solvents include, but are notlimited to; ketones such as cyclohexanone and methyl-2-n-amylketone;alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol,1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propyleneglycol methyl ether (PGME), propylene glycol ethyl ether (PGEE),ethylene glycol monomethyl ether, propylene glycol monoethyl ether,ethylene glycol monoethyl ether, propylene glycol dimethyl ether, anddiethylene glycol dimethyl ether, anisole; esters such as propyleneglycol monomethyl ether acetate (PGMEA), propylene glycol monoethylether acetate, ethyl lactate (EL), methyl hydroxyisobutyrate (HBM),ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, andpropylene glycol mono-tert-butyl ether acetate; lactones such asgamma-butyrolactone; and any combination of the foregoing. Preferredsolvents are PGME, PGEE, PGMEA, EL, HBM, and combinations thereof.

The present coating compositions may also comprise one or more coatingadditives that are typically used in such coatings, such as curingagents, crosslinking agents, surface leveling agents, and the like. Theselection of such optional additives and their amounts are well withinthe ability of those skilled in the art. Curing agents are typicallypresent in an amount of from 0 to 20 wt % based on total solids, andpreferably from 0 to 3 wt %. Crosslinking agents are typically used inan amount of from 0 to 30 wt % based on total solids, and preferablyfrom 3 to 10 wt %. Surface leveling agents are typically used in anamount of from 0 to 5 wt % based on total solids, and preferably from 0to 1 wt %. The selection of such optional additives and their amountsused are within the ability of those skilled in the art.

Curing agents may optionally be used in the coating compositions to aidin the curing of the deposited curable compound. A curing agent is anycomponent which causes curing of the curable compound on the surface ofthe substrate. Preferred curing agents are acids and thermal acidgenerators. Suitable acids include, but are not limited to: arylsulfonicacids such as p-toluenesulfonic acid; alkyl sulfonic acids such asmethanesulfonic acid, ethanesulfonic acid, and propanesulfonic acid;perfluoroalkylsulfonic acids such as trifluoromethanesulfonic acid; andperfluoroarylsulfonic acids. A thermal acid generator is any compoundwhich liberates acid upon exposure to heat. Thermal acid generators arewell-known in the art and are generally commercially available, such asfrom King Industries, Norwalk, Conn. Exemplary thermal acid generatorsinclude, without limitation, amine blocked strong acids, such as amineblocked sulfonic acids such as amine blocked dodecylbenzenesulfonicacid. It will also be appreciated by those skilled in the art thatcertain photoacid generators are able to liberate acid upon heating andmay function as thermal acid generators.

Any suitable crosslinking agent may be used in the present compositions,provided that such crosslinking agent has at least 2, and preferably atleast 3, moieties capable of reacting with the present aromatic resinreaction products under suitable conditions, such as under acidicconditions. Exemplary crosslinking agents include, but are not limitedto, novolac resins, epoxy-containing compounds, melamine compounds,guanamine compounds, isocyanate-containing compounds, benzocyclobutenes,and the like, and preferably any of the foregoing having 2 or more,preferably 3 or more, and more preferably 4, substituents selected frommethylol, C₁-C₁₀alkoxymethyl, and C₂-C₁₀acyloxymethyl. Examples ofsuitable crosslinking agents are those shown by formulae (3) and (4).

Such crosslinking agents are well-known in the art, and are commerciallyavailable from a variety of sources.

The present coating compositions may optionally include one or moresurface leveling agents (or surfactants). While any suitable surfactantmay be used, such surfactants are typically non-ionic. Exemplarynon-ionic surfactants are those containing an alkyleneoxy linkage, suchas ethyleneoxy, propyleneoxy, or a combination of ethyleneoxy andpropyleneoxy linkages.

The present coating compositions may be coated on an electronic devicesubstrate by any suitable means, such as spin-coating, slot-die coating,doctor blading, curtain coating, roller coating, spray coating, dipcoating, and the like. Spin-coating is preferred. In a typicalspin-coating method, the present compositions are applied to a substratewhich is spinning at a rate of 500 to 4000 rpm for a period of 15 to 90seconds to obtain a desired layer of the coating composition on theelectronic device substrate. It will be appreciated by those skilled inthe art that the height of the coating composition layer may be adjustedby changing the spin speed.

After being coated on the substrate, the coating composition layer isoptionally baked at a relatively low temperature to remove any organicsolvent and other relatively volatile components from the layer.Typically, the substrate is baked at a temperature of 80 to 150° C.,although other suitable temperatures may be used. The baking time istypically from 10 seconds to 10 minutes, and preferably from 30 secondsto 5 minutes, although longer or shorter times may be used. When thesubstrate is a wafer, such baking step may be performed by heating thewafer on a hot plate. Following solvent removal, a layer, film orcoating of the curable compound on the substrate surface is obtained.

The curable compound layer is then sufficiently cured to form anaromatic underlayer such that the film does not intermix with asubsequently applied coating layer, such as a photoresist or other layercoated directly on the aromatic underlayer. The underlayer may be curedin an oxygen-containing atmosphere, such as air, or in an inertatmosphere, such as nitrogen, and preferably in an oxygen-containingatmosphere. The curing conditions used are those sufficient to cure thefilm such that it does not intermix with a subsequently applied organiclayer, such as a photoresist layer, while still maintaining the desiredantireflective properties (n and k values) and etch selectivity of theunderlayer film. This curing step is conducted preferably on a hotplate-style apparatus, though oven curing may be used to obtainequivalent results. Typically, such curing is performed by heating theunderlayer at a curing temperature of ≥150° C., preferably ≥170° C., andmore preferably ≥200° C. The curing temperature selected should besufficient to cure the aromatic underlayer. A suitable temperature ragefor curing the aromatic underlayer is 150 to 400° C., preferably from170 to 350° C., and more preferably from 200 to 250° C. Such curing stepmay take from 10 sec. to 10 min., preferably from 1 to 3 min., and morepreferably from 1 to 2 min., although other suitable times may be used.

The initial baking step may not be necessary if the curing step isconducted in such a way that rapid evolution of the solvents and curingby-products is not allowed to disrupt the underlayer film quality. Forexample, a ramped bake beginning at relatively low temperatures and thengradually increasing to a temperature of ≥200° C. can give acceptableresults. It can be preferable in some cases to have a two-stage curingprocess, with the first stage being a lower bake temperature of lessthan 150° C., and the second stage being a higher bake temperature of≥200° C. Two stage curing processes facilitate uniform filling andplanarization of pre-existing substrate surface topography, for examplefilling of trenches and vias.

After curing of the underlayer, one or more processing layers, such asphotoresists, silicon-containing layers, hardmask layers, bottomantireflective coating (or BARC) layers, and the like, may be coated onthe cured underlayer. For example, a photoresist may be coated, such asby spin coating, directly on the surface of a silicon-containing layeror other middle layer which is directly on the resin underlayer, or,alternatively, the photoresist may be coated directly on the curedunderlayer. A wide variety of photoresists may be suitably used, such asthose used in 193 nm lithography, such as those sold under the EPIC™brand available from Dow Electronic Materials (Marlborough, Mass.).Suitable photoresists may be either positive tone development ornegative tone development resists. Following coating, the photoresistlayer is then imaged (exposed) using patterned actinic radiation, andthe exposed photoresist layer is then developed using the appropriatedeveloper to provide a patterned photoresist layer. The pattern is nexttransferred from the photoresist layer to the underlayers by anappropriate etching techniques. Typically, the photoresist is alsoremoved during such etching step. Next, the pattern is transferred tothe substrate and the underlayer removed by appropriate etchingtechniques known in the art, such as by plasma etching. Followingpatterning of the substrate, the underlayer is removed usingconventional techniques. The electronic device substrate is thenprocessed according to conventional means.

The cured underlayer may be used as the bottom layer of a multilayerresist process. In such a process, a layer of the coating composition iscoated on a substrate and cured as described above. Next, one or moremiddle layers are coated on the aromatic underlayer. For example, asilicon-containing layer or a hardmask layer is coated directly on thearomatic underlayer. Exemplary silicon-containing layers, such as asilicon-BARC, may be deposited by spin coating on the underlayerfollowed by curing, or an inorganic silicon layer such as SiON or SiO₂may be deposited on the underlayer by chemical vapor deposition (CVD).Any suitable hardmask may be used and may be deposited on the underlayerby any suitable technique, and cured as appropriate. Optionally, anorganic BARC layer may be disposed directly on the silicon-containinglayer or hardmask layer, and appropriately cured. Next, a photoresist,such as those used in 193 nm lithography, is coated directly on thesilicon-containing layer (in a trilayer process) or directly on theorganic BARC layer (in a quadlayer process). The photoresist layer isthen imaged (exposed) using patterned actinic radiation, and the exposedphotoresist layer is then developed using the appropriate developer toprovide a patterned photoresist layer. The pattern is next transferredfrom the photoresist layer to the layer directly below it, byappropriate etching techniques known in the art, such as by plasmaetching, resulting in a patterned silicon-containing layer in a trilayerprocess and a patterned organic BARC layer in a quadlayer process. If aquadlayer process is used, the pattern is next transferred from theorganic BARC layer to the silicon-containing layer or hardmask layerusing appropriate pattern transfer techniques, such as plasma etching.After the silicon-containing layer or hardmask layer is patterned, thearomatic underlayer is then patterned using appropriate etchingtechniques, such as O₂ or CF₄ plasma. Any remaining patternedphotoresist and organic BARC layers are removed during etching of thearomatic underlayer. Next, the pattern is transferred to the substrate,such as by appropriate etching techniques, which also removes anyremaining silicon-containing layer or hardmask layer, followed byremoval of any remaining patterned aromatic underlayer to provide apatterned substrate.

The cured underlayer of the present invention may also be used in aself-aligned double patterning process. In such a process, a layer ofthe present coating composition is coated on a substrate, such as byspin-coating. Any remaining organic solvent is removed and the coatingcomposition layer is cured to form a cured underlayer. A suitable middlelayer, such as a silicon-containing layer is coated on the curedunderlayer. A layer of a suitable photoresist is then coated on themiddle layer, such as by spin coating. The photoresist layer is thenimaged (exposed) using patterned actinic radiation, and the exposedphotoresist layer is then developed using the appropriate developer toprovide a patterned photoresist layer. The pattern is next transferredfrom the photoresist layer to the middle layer and the cured underlayerby appropriate etching techniques to expose portions of the substrate.Typically, the photoresist is also removed during such etching step.Next, a conformal silicon-containing layer is disposed over thepatterned cured underlayer and exposed portions of the substrate. Suchsilicon-containing layer is typically an inorganic silicon layer such asSiON or SiO₂ which is conventionally deposited by CVD. Such conformalcoatings result in a silicon-containing layer on the exposed portions ofthe substrate surface as well as over the underlayer pattern, that is,such silicon-containing layer substantially covers the sides and top ofthe patterned underlayer. Next, the silicon-containing layer ispartially etched (trimmed) to expose a top surface of the patternedpolyarylene resin underlayer and a portion of the substrate. Followingthis partial etching step, the pattern on the substrate comprises aplurality of features, each feature comprising a line or post of thecured underlayer with the silicon-containing layer directly adjacent tothe sides of each cured underlayer feature. Next, the cured underlayeris removed, such as by etching, to expose the substrate surface that wasunder the cured underlayer pattern, and providing a patternedsilicon-containing layer on the substrate surface, where such patternedsilicon-containing layer is doubled (that is, twice as many lines and/orposts) as compared to the patterned cured underlayer.

The coating compositions of the invention are also useful in formingplanarizing layers, gap filling layers, and protective layers in themanufacture of integrated circuits. When used as such planarizinglayers, gap filling layers, or protective layers, one or moreintervening material layers, such as silicon-containing layers, otheraromatic resin layers, hardmask layers, and the like, are typicallypresent between the cured layer of the present coating composition andany photoresist layer. Typically, such planarizing layers, gap fillinglayers, and protective layers are ultimately patterned. A gap-fillingprocess according to the invention comprises: (a) providing asemiconductor substrate having a relief image on a surface of thesubstrate, the relief image comprising a plurality of gaps to be filled;(b) applying a gap-fill composition over the relief image, wherein thegap-fill composition comprises: one or more curable compounds comprisingan aromatic core chosen from a C₅ aromatic ring and a C₉₋₃₀ fusedaromatic ring system and three or more substituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is a substituent chosen fromchosen from OR¹, protected hydroxyl, carboxyl, protected carboxyl, SR¹,protected thiol, —O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ ischosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀aryl; each R² is chosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturatedhydrocarbyl, C₅₋₃₀ aryl, C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1to 4; and * denotes the point of attachment to the aromatic core; and(ii) one or more organic solvents; and (c) heating the gap-fillcomposition at a temperature to cure the one or more curable compounds.The present compositions substantially fill, preferably fill, and morepreferably fully fill, a plurality of gaps in a semiconductor substrate.

The compounds of the invention have good gap-filling properties. Filmsformed from the compounds of the invention have good planarization,solvent resistance and reduced defect formation as compared to compoundsdisclosed in U.S. Pat. No. 9,581,905.

EXAMPLE 1

1,3,5-Tribromobenzene (2.36 g), cuprous iodide (0.21 g) andtriethylamine (3.42 g) were added to 20 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to thereaction mixture, and the mixture was heated to 70° C. 4-Ethynylphenylacetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and thesolution was then slowly added to reaction mixture by way of an additionfunnel. After completion of addition, the reaction mixture was stirredfor overnight at 70° C. under nitrogen. After the reaction wascompleted, the reaction mixture was cooled to room temperature, filteredand solvents were evaporated. The residue was purified by columnchromatography to give 1,3,5-tris((4-acetoxyphenyl)ethynyl)benzene(Compound I1) as a light yellow solid, 3.5 g (84% yield). The reactionis shown in the following reaction scheme.

EXAMPLE 2

1,3,5-Tribromobenzene (2.36 g), cuprous iodide (0.21 g) andtriethylamine (3.42 g) were added to 20 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to thereaction mixture, and the mixture was heated to 70° C. 4-Ethynylphenylacetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and thesolution was then slowly added to reaction mixture by way of an additionfunnel. After completion of addition, the reaction mixture was stirredfor overnight at 70° C. under nitrogen. After the reaction wascompleted, the reaction mixture was cooled to room temperature, filteredand solvents were evaporated. The residue was purified by columnchromatography to give a light yellow solid. This obtained solid wasthen dissolved in THF (35 g) under nitrogen. Lithium hydroxidemonohydrate (0.94 g) and water (8 g) were added, and the reactionmixture was stirred at 60° C. for 1 hr. The reaction mixture was thendiluted with ethyl acetate and then treated with hydrochloric acid untilthe pH of the aqueous layer was 1. The organic phase was separated andthe aqueous phase was extracted with ethyl acetate. The organic layerswere combined, and washed with water. The solvent was removed undervacuum to obtain 1,3,5-tris((4-hydroxyphenyl)ethynyl)benzene (CompoundI2) as a light yellow solid, 2.6 g (81% yield). The reaction is shown inthe following reaction scheme.

EXAMPLE 3

4-Iodophenyl acetate (24.75 g), cuprous iodide (0.17 g) andtriethylamine (27.32 g) were added to 22.82 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.63 g) was added to thereaction mixture, and the mixture was heated to 70° C. A solution of1,3,5-triethynylbenzene (4.5 g) in degassed 1,4-dioxane (20 g) was thenslowly added to reaction mixture via syringe pump. After completion ofaddition, the reaction was stirred for overnight at 70° C. undernitrogen. After the reaction was completed, the reaction mixture wascooled to room temperature, and solvents were evaporated. The residuewas diluted with ethyl acetate and filtered to remove the solid. Thesolution was evaporated, and the residue was purified by columnchromatography to give a light yellow solid. This obtained solid wasthen dissolved in THF (38 g) under nitrogen. Lithium hydroxidemonohydrate (3.81 g) and water (16 g) were added, and the mixture wasstirred at 60° C. for 1 hr. The mixture was then cooled to roomtemperature, and the solvent was removed. The residue was diluted withethyl acetate and water, and then treated with hydrochloric acid untilthe pH of the aqueous layer was 1. The organic phase was separated andthe aqueous phase was extracted with ethyl acetate. The organic layerswere combined, and washed with water. The solvent was removed undervacuum, and the residue was purified by column chromatography to obtain1,3,5-tris((4-hydroxyphenyl)ethynyl)benzene (Compound I2) as a lightyellow solid, 7.7 g (61% yield). The reaction is shown in the followingreaction scheme.

EXAMPLE 4

1,3,5-Tribromobenzene (3.12 g), cuprous iodide (0.29 g) andtriethylamine (4.55 g) were added to 22 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.70 g) was added to thereaction mixture, and the mixture was heated to 70° C.1-ethynyl-4-methoxybenzene (5.28 g) was dissolved in degassed1,4-dioxane (20 g), and the solution was then slowly added to reactionmixture by way of an addition funnel. After completion of addition, thereaction mixture was stirred overnight at 70° C. under nitrogen. Afterreaction was completed, the mixture was cooled to room temperature,filtered and solvents were evaporated. The residue was purified bycolumn chromatography to give1,3,5-tris((4-methoxyphenyl)ethynyl)benzene (Compound I3) as a lightyellow solid, 4.0 g (85% yield). The reaction is shown in the followingreaction scheme.

EXAMPLE 5

1,3,5-Tribromobenzene (3.12 g), cuprous iodide (0.29 g) andtriethylamine (4.55 g) were added to 22 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.70 g) was added to thereaction mixture, and the mixture was heated to 70° C. 4-Ethynylaniline(4.68 g) was dissolved in degassed 1,4-dioxane (20 g), and the solutionwas then slowly added to the reaction mixture by way of an additionfunnel. After completion of addition, the reaction mixture was stirredovernight at 70° C. under nitrogen. After the reaction was completed,the reaction mixture was cooled to room temperature, filtered andsolvents were evaporated. The residue was purified by columnchromatography to give 1,3,5-tris((4-aminophenyl)ethynyl)benzene(Compound I4) as a yellow solid, 1.5 g (36% yield). The reaction isshown in the following reaction scheme.

EXAMPLE 6

1,3,5-Tribromobenzene (15.0 g) was added to 40.0 g of 1,4-dioxane atroom temperature to yield a clear solution. Triethylamine (14.5 g) andcuprous iodide (0.91 g) were added to the reaction mixture. The reactionmixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (1.00 g) was added to thereaction mixture. Next, 22.9 g of 4-fluorophenylacetylene was slowlyadded to reaction mixture via an addition funnel. After completion ofaddition, the reaction was stirred for 24 hr. at 55° C. under nitrogen.The reaction mixture was filtered and solvents were evaporated. Theresidue was dissolved in heptanes and filtered through a silica plug.After filtration, the solvents were removed to yield1,3,5-tris((4-fluorophenyl)ethynyl)benzene (Compound IS) as a lightyellow solid (8.0 g) in 39% yield. The reaction is shown in thefollowing reaction scheme.

EXAMPLE 7

5,5′—Oxybis(1,3-dibromobenzene) (3.61 g), cuprous iodide (0.21 g) andtriethylamine (3.42 g) were added to 20 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to thereaction mixture, and the mixture was heated to 70° C. 4-Ethynylphenylacetate (4.81 g) was dissolved in degassed 1,4-dioxane (17 g), and thesolution was then slowly added to reaction mixture by way of an additionfunnel. After completion of addition, the reaction mixture was stirredovernight at 70° C. under nitrogen. After the reaction was completed,the reaction mixture was cooled to room temperature, filtered andsolvents were evaporated. The residue was purified by chromatography togive a light yellow solid. This obtained solid was then dissolved in THF(40 g) under nitrogen. Lithium hydroxide monohydrate (1.26 g) and water(10 g) were added, and the mixture was stirred at 60° C. for 1 hr. Thereaction mixture was then diluted with ethyl acetate and then treatedwith hydrochloric acid until the pH of the aqueous layer was 1. Theorganic phase was separated and the aqueous phase was extracted withethyl acetate. The organic layers were combined, and washed with water.The solvent was removed under vacuum, and the residue was purified bycolumn chromatography to give5,5′-oxybis(1,3-di((4-hydroxyphenyl)ethynyl)benzene) (Compound 16) as alight yellow solid, 3.1 g (65% yield). The reaction is shown in thefollowing reaction scheme.

EXAMPLE 8

9,9-Bis(6-(3,5-dibromophenoxy)naphthalen-2-yl)-9H-fluorene (6.85 g),cuprous iodide (0.21 g) and triethylamine (3.42 g) were added to 25 g of1,4-dioxane at room temperature. The reaction mixture was purged withnitrogen for 1 hr. Bis(triphenylphosphine)palladium(II) chloride (0.53g) was added to the reaction mixture, and the mixture was heated to 70°C. 4-Ethynylphenyl acetate (4.81 g) was dissolved in degassed1,4-dioxane (22 g), and the solution was then slowly added to reactionmixture by way of an addition funnel. After completion of addition, thereaction mixture was stirred overnight at 70° C. under nitrogen. Afterthe reaction was completed, the reaction mixture was cooled to roomtemperature, filtered and solvents were evaporated. The residue waspurified by chromatography to give a light yellow solid. This obtainedsolid was then dissolved in THF (40 g) under nitrogen. Lithium hydroxidemonohydrate (1.26 g) and water (10 g) were added, and the mixture wasstirred at 60° C. for 1 hr. The reaction mixture was then diluted withethyl acetate and then treated with hydrochloric acid until the pH ofthe aqueous layer was 1. The organic phase was separated and the aqueousphase was extracted with ethyl acetate. The organic layers werecombined, and washed with water. The solvent was removed under vacuum,and the residue was purified by column chromatography to give9,9-bis(6-(3,5-di((4-hydroxyphenyl)ethynyl)phenoxy)naphthalen-2-yl)-9H-fluorene(Compound 17) as a light yellow solid, 4.7 g (59% yield). The reactionis shown in the following reaction scheme.

EXAMPLE 9

1,3,5-Trisbromobenzene (2.83 g), cuprous iodide (0.17 g) andtriethylamine (4.10 g) were added to 20 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.32 g) was added to thereaction mixture, and the mixture was heated to 70° C.2-((6-Ethynylnaphthalen-2-yl)oxy)tetrahydro-2H-pyran (6.81 g) wasdissolved in degassed 1,4-dioxane (13 g), and the solution was thenslowly added to reaction mixture by way of an addition funnel. Aftercompletion of addition, the reaction mixture was stirred overnight at70° C. under nitrogen. After the reaction was completed, the reactionmixture was cooled to room temperature, filtered and solvents wereevaporated. The residue was purified by chromatography to give whitesolid. This obtained solid was then dispersed in MeOH (54 g) undernitrogen. 12N HCl (4.5 g) and water (54 g) were added, and the mixturewas refluxed overnight at 60° C. The reaction mixture was then cooled toroom temperature, and solvent was removed under vacuum. The residue wasdiluted with ethyl acetate, and the organic phase was separated and theaqueous phase was extracted with ethyl acetate. The organic layers werecombined, and washed with water. The solvent was removed under vacuum,and the residue was purified by column chromatography to give1,3,5-tris((2-hydroxynaphthyl-6-ethynyl)benzene (Compound 18) as a whitesolid 1.1 g (21% yield). The reaction is shown in the following reactionscheme.

Compound I2 (6.0 g) in 46 g anhydrous DMF was stirred at roomtemperature for 15 minutes. The mixture was heated to 30° C. and 10.34 gK₂CO₃ was then added. The reaction was then allowed to heat to 50° C.and 8.63 g propargyl bromide (80% in toluene) solution was addeddropwise via additional funnel. The reaction mixture was heated at 50°C. for 24 hours. The reaction was then allowed to cool down to roomtemperature and was filtered to remove most of K₂CO₃. The organic wasprecipitated into 2 L water, stirred at room temperature for 0.5 h. Theprecipitated polymer was collected by filtration to give solid (17.8 g)after dried under vacuum at 35° C. for 1 day.

COMPARATIVE EXAMPLE 1

1,3,5-Tris(4-bromophenyl)benzene (4.05 g), cuprous iodide (0.21 g) andtriethylamine (3.42 g) were added to 20 g of 1,4-dioxane at roomtemperature. The reaction mixture was purged with nitrogen for 1 hr.Bis(triphenylphosphine)palladium(II) chloride (0.53 g) was added to thereaction mixture, and the mixture was heated to 70° C. 4-Ethynylphenylacetate (4.81 g) was dissolved in degassed 1,4-dioxane (14 g), and thesolution was then slowly added to reaction mixture by way of an additionfunnel. After completion of addition, the reaction mixture was stirredovernight at 70° C. under nitrogen. After the reaction was completed,the reaction mixture was cooled to room temperature, filtered andsolvents were evaporated. The residue was purified by chromatography togive a light yellow solid. This obtained solid was then dissolved in THF(35 g) under nitrogen. Lithium hydroxy monohydrate (0.94 g) and water (8g) were added, and the mixture was stirred at 60° C. for 1 hr. Thereaction mixture was then diluted with ethyl acetate and then treatedwith hydrochloric acid until the pH of the aqueous layer was 1. Theorganic phase was separated and aqueous phase was extracted with ethylacetate. The organic layers were combined, and washed with water. Thesolvent was removed under vacuum, and the residue was purified by columnchromatography to give1,3,5-tris((4-(4-hydroxyphenyl)ethynyl)phenyl)benzene (Comparative 1) asa light yellow solid, 2.2 g (44% yield). The reaction is shown in thefollowing reaction scheme.

EXAMPLE 10

Solubility was evaluated by mixing a compound of the invention with eachof PGME and PGMEA at 5% solids. Those mixtures were visibly inspected aswell as checked using a turbidity meter (Orbeco-Hellige Co). If theturbidity value was less than 1, the compound was rated soluble (“S”)and if the turbidity value was greater than 1, it was rated not soluble(“NS”). The results are reported in Table 1. As can be seen from thesedata, the compounds of the invention and the Comparative compound areall soluble in each of PGME and PGMEA.

TABLE 1 Solubility (5% solids) Entry No. Compound PGMEA PGME 1 I2 S S 2I6 S S 3 I9 S S 4 Comparative 1 S S

EXAMPLE 11

Thermal stability of compounds of the invention was evaluated using aThermal Gravimetric Analyzer (TGA) Q500 from TA-Instruments, under thefollowing conditions: under N₂, ramp at 10° C./min. to 700° C.; andunder air, ramp at 10° C./min. to 700° C. The temperature at which thematerials lost 5% of their weight (“Td_(5%)”) are reported in Table 2.

TABLE 2 Td_(5%) (° C.) Entry No. Compound Under N₂ Under Air 1 I2 504470 2 I6 503 469 3 I9 471 398 4 Comparative 1 526 492

EXAMPLE 12

Solvent strip resistance was measured as an indication of filmcrosslinking Compositions of compounds of the invention and ofComparative Compound 1 were prepared in a mixture of PGMEA and benzylbenzoate at 4.5% solids. Each composition was spin-coated on an 8″ (200mm) silicon wafer at a rate of 1500 rpm using ACT-8 Clean Track (TokyoElectron Co.), and then baked at the temperature reported in Table 3 for60 seconds to form a film. Initial film thickness was measured using anOptiProbe™ from Therma-Wave Co. Next, a commercial remover, OK73(PGME/PGMEA=70/30), was applied to each of the films for 90 secondsfollowed by a post strip baking step at 105° C. for 60 seconds. Thethickness of each film following post strip baking was again measured todetermine the amount of film thickness lost. The difference in filmthickness before and after contact with the remover is reported in Table3 as the percentage of film thickness remaining. As can be seen from thedata, films formed from the compounds of the invention retained greaterthan 99% of their thickness, whereas the film formed from ComparativeCompound 1 retained only 12% film thickness (that is, it lost 88% of itsthickness) after contact with the remover.

TABLE 3 Entry No. Compound % Film Remaining 1 I2 >99 (230° C.) 2 I6 >99(230° C.) 3 I9 >99 (300° C.) 4 Comparative 1  12 (230° C.)

EXAMPLE 13

Compositions of compounds of the invention and of Comparative Compound 1were prepared in a mixture of PGMEA and benzyl benzoate at 4.5% solids.Each composition was spin-coated on an 8″ (200 mm) silicon wafer at arate of 1500 rpm using ACT-8 Clean Track (Tokyo Electron Co.), and thenbaked at the temperatures identified in Table 4 for 60 seconds to form acured film. Optical constants were measured by Vacuum Ultra-VioletVariable Angle Ellipsometer (VUV-VASE, from Woollam Co.) at 193 nm, andare reported in Table 4.

TABLE 4 Refractive Index/ Absorbance at 193 nm Entry No. Compound(Temperature) n k 1 I2 (240° C.) 1.41 0.25 2 I9 (300° C.) 1.49 0.50 3Comparative 1 (300° C.) 1.42 0.63

EXAMPLE 14

Compounds of the invention were evaluated to determine their gap-fillingproperties. Gap fill templates were created at CNSE Nano-FAB (Albany,N.Y.). The template had SiO₂ film thickness of 100 nm, and various pitchand patterns. The template coupons were baked at 150° C. for 60 secondsas a dehydration bake prior to coating the coupons with the presentcompositions. Each coating composition (4.5% solids in a mixture ofPGMEA, benzyl benzoate and PolyFox PF656) was coated on a templatecoupon using an ACT-8 Clean Track (Tokyo Electron Co.) spin coater and aspin rate of 1500 rpm+/−200 rpm. The target film thickness was 100 nmafter curing, and the composition dilution was adjusted accordingly togive approximately the target film thickness after curing. The filmswere cured by placing the wafer on a hot plate at the temperatureidentified in Table 5 for 60 sec. Cross-section scanning electronmicroscope (SEM) images of the coated coupons were collected using aHitachi S4800 SEM (from Hitachi High Technologies). Planarizationquality of the films was obtained from the SEM images using Hitachioffline CD measurement software or CDM software by measuring thedifference in thickness between dense trench and open area of the film(ΔFT). Films having a ΔFT<20 nm were considered to have “Good”planarization and films having a ΔFT>20 nm were considered to have“Poor” planarization. Gap filling was evaluated by visually inspectingthe SEM images to see if there were any voids or bubbles in the trenchpatterns. Films having no voids in the trench patterns were consideredto have “Good” gap fill and films having voids in the trench patterswere considered to have “Poor” gap fill. These results are reported inTable 5.

TABLE 5 Sample No. Compound (Temperature) Planarization Gap Fill 1 I2(240° C.) Good Good 2 I6 (240° C.) Good Good 3 I8 (300° C.) Good Good 4I9 (300° C.) Good Good 5 Comparative 1 (300° C.) Poor Good

EXAMPLE 15

Compositions of compounds of the invention and of Comparative Compound 1were prepared in PGMEA at 4.5% solids. Each composition was spin-coatedon an 8″ (200 mm) silicon wafer at a rate of 1500 rpm using an ACT-8Clean Track (Tokyo Electron Co.), and then baked at the temperaturesreported in Table 6 for 60 sec. to form a cured film. Coating qualitywas evaluated by visually inspecting the film, and the results arereported in Table 6.

TABLE 6 Entry No. Compound (Temperature) Coating Quality 1 I2 (240° C.)Good 2 I9 (300° C.) Good 3 Comparative 1 (300° C.) Poor

EXAMPLE 16

Each underlayer solution (4.5% solids in a mixture of PGMEA and benzylbenzoate) was spin coated at 1500 rpm on 200 mm silicon wafers using anACT-8 Clean Track with targeted film thickness of 100 nm after curing. Avirgin silicon wafer was placed upside down on top of the coated waferwith three (2 mm) spacers on the edge. The wafer stack was baked at thetemperatures identified in Table 7 for 60 sec. on a hot plate with thecoated wafer at the bottom. The top wafer was inspected for haze (whichindicates sublimation) and defect using SP2 defect tool (from KLA-TencorCorporation) with 500 nm sensitivity. As can be seen from the data inTable 7, Comparative Compound 1 gives significantly higher defect countand defect density than does Compound I2 of the present invention.

TABLE 7 Sublimation Defect (Less spacer defects) Entry No. Compound(Temperature) Defect Count Defect Density 1 I2 (240° C.) <8 <0.03 2Comparative 1 (300° C.) >91000 >325

What is claimed is:
 1. A method comprising: (a) providing an electronicdevice substrate; (b) coating a layer of a coating compositioncomprising one or more curable compounds on a surface of the electronicdevice substrate, wherein the one or more curable compounds comprise anaromatic core chosen from a C₅₋₆ aromatic ring and a C₉₋₃₀ fusedaromatic ring system and three or more substituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is a substituent chosen fromOR¹, protected hydroxyl, carboxyl, protected carboxyl, SR¹, protectedthiol, —O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H,C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² ischosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core; (c) curing the layer of thecurable compound to form an underlayer; (d) coating a layer of aphotoresist on the underlayer; (e) exposing the photoresist layer toactinic radiation through a mask; (f) developing the exposed photoresistlayer to form a resist pattern; and (g) transferring the pattern to theunderlayer to expose portions of the electronic device substrate.
 2. Themethod of claim 1 further comprising the steps of patterning thesubstrate; and then removing the patterned underlayer.
 3. The method ofclaim 1 further comprising the step of coating one or more of asilicon-containing layer, an organic antireflective coating layer and acombination thereof over the underlayer before step (d).
 4. The methodof claim 3 further comprising the step of transferring the pattern tothe one or more of the silicon-containing layer, the organicantireflective coating layer and the combination thereof after step (f)and before step (g).
 5. The method of claim 1 wherein each Z isindependently chosen from OR¹, protected hydroxyl, carboxyl, protectedcarboxyl, SH, fluorine and NHR².
 6. The method of claim 1 whereinaromatic core is chosen from pyridine, benzene, naphthalene, quinoline,isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene.
 7. The method of claim 1 wherein each Ar¹ isindependently chosen from pyridine, benzene, naphthalene, quinoline,isoquinoline, anthracene, phenanthrene, pyrene, coronene, triphenylene,chrysene, phenalene, benz[a]anthracene, dibenz[a,h]anthracene, andbenzo[a]pyrene.
 8. The method of claim 1 wherein the coating compositionfurther comprises one or more of an organic solvent, a curing agent, anda surface leveling agent.
 9. An electronic device comprising anelectronic device substrate having a layer of a polymer comprising aspolymerized units one or more curable compounds on a surface of theelectronic device substrate, wherein the one or more curable compoundscomprise an aromatic core chosen from a C₅₋₆ aromatic ring and a C₉₋₃₀fused aromatic ring system and three or more substituents of formula (1)

wherein at least two substituents of formula (1) are attached to thearomatic core; and wherein Ar¹ is an aromatic ring or fused aromaticring system having from 5 to 30 carbons; Z is a substituent chosen fromOR¹, protected hydroxyl, carboxyl, protected carboxyl, SR¹, protectedthiol, —O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H,C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² ischosen from H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x is an integer from 1 to 4; and * denotes thepoint of attachment to the aromatic core.
 10. A compound of formula (2)

wherein Ar^(c) is an aromatic core having from 5 to 30 carbon atoms;Ar¹, Ar², and Ar³ are each independently an aromatic ring or fusedaromatic ring system having from 5 to 30 carbons; Y is a single covalentchemical bond, a divalent linking group, or a trivalent linking group;Z¹ and Z² are independently a substituent chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosenfrom H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to4; y1+each y2≥3; w=0 to 2; and z equals 0 to 2; wherein z=1 when Y is asingle covalent chemical bond or a divalent linking group; and z=2 whenY is a trivalent linking group; provided that Ar^(c) and each Ar¹ arenot phenyl when w=0.
 11. A method comprising: (a) providing anelectronic device substrate; (b) coating a layer of a coatingcomposition comprising one or more curable compounds of formula (2)

wherein Ar^(c) is an aromatic core having from 5 to 30 carbon atoms;Ar¹, Ar², and Ar³ are each independently an aromatic ring or fusedaromatic ring system having from 5 to 30 carbons; Y is a single covalentchemical bond, a divalent linking group, or a trivalent linking group;Z¹ and Z² are independently a substituent chosen from OR¹, protectedhydroxyl, carboxyl, protected carboxyl, SR¹, protected thiol,—O—C(═O)—C₁₋₆-alkyl, halogen, and NHR²; each R¹ is chosen from H, C₁₋₁₀alkyl, C₂₋₁₀ unsaturated hydrocarbyl, and C₅₋₃₀ aryl; each R² is chosenfrom H, C₁₋₁₀ alkyl, C₂₋₁₀ unsaturated hydrocarbyl, C₅₋₃₀ aryl,C(═O)—R¹, and S(═O)₂—R¹; x1=1 to 4; x2=1 to 4; y1=2 to 4; each y2=0 to4; y1+each y2≥3; w=0 to 2; and z equals 0 to 2; wherein z=1 when Y is asingle covalent chemical bond or a divalent linking group; and z=2 whenY is a trivalent linking group on a surface of the electronic devicesubstrate; (c) curing the layer of the curable compound to form anunderlayer; (d) coating a layer of a photoresist on the underlayer; (e)exposing the photoresist layer to actinic radiation through a mask; (f)developing the exposed photoresist layer to form a resist pattern; and(g) transferring the pattern to the underlayer to expose portions of theelectronic device substrate.